The following are prior art patent documents that disclose the use of channels for routing migratory fish around a dam in a river. U.S. Pat. No. 3,772,891, granted Nov. 20, 1973, to John E. Raistakka; U.S. Pat. No. 3,938,340, granted Feb. 17, 1976, to Dalles I. Downs; U.S. Pat. No. 4,740,105, granted Apr. 26, 1988, to Jon R. Wollander; U.S Patent Pub. No. U.S. 2002/0187006 A1, published Dec. 12, 2002, naming Gordon Charles Burns II as the inventor; Japanese Patent Publication No. JP409250123 A, published Sep. 22, 1997, listing Kunitaka Sasaki as the inventor; Japanese Patent Publication No. JP410102463 A, published Apr. 21, 1998, naming Kenichi Watabe as the inventor; Japanese Patent Publication No. JP411315528 A, published Nov. 16, 1999, naming Kunitaka Sasaki as the inventor; Japanese Patent Publication No. JP 02000233194 A, published Aug. 29, 2000, naming Masahiro Kishimoto as the inventor; Japanese Patent Publication No. JP2003147754 A, published May 21, 2003, naming Tohoku Sekizai Block Ka as the assignee; and Japanese Patent Publication No. JP404200696 A, published Jul. 21, 1992, naming Takao Tawara as the inventor.
U.S. Pat. No. 3,772,891 discloses providing a fish conduit that extends from a region below a dam to a region above the dam. The conduit is shown in the nature of sections of pipe connected together to provide a tubular conduit. Published patent application U.S. 2002/0187006 A1 teaches using a man made artificial stream in place of the tubular conduit. The stream connects a region of the river below the dam with a region of the river above the dam. The artificial stream is in the nature of a meandering nature-like channel constructed of concrete, shotcreat or gunite that simulates a waterway bed condition. The other patents of the above identified group of patents relate for the most part to specific channel structures for the passage of fish around a dam in a river.
There is a need for a simple yet effective way of providing for upstream and downstream fish migration past a series of dams in a river while retaining the economic benefits of the dams. An object of the present invention is to supply this need.